Tap-grinding machine.



N10. 856,978. PA'IENTBD JUNE 11, 1907. 0. M. MOWAT. TAP GRINDING MACHINE.

APPLICATION FILED NOV.3, 1905.

' asuma-SHEET 1.

WITNESSES PATENTED JUNE 1l, 1907.

0. M. MUWAT. TAP GRINDING MACHINE.

APPLICATION FILED NOV-3. 1905.

3 SHEETS-SHEET 2.

No. 856,978. PATENTBD JUNE ll, 1907. O. M. MOWAT.

TAP GRINDING MACHINE.- APPLIoATIoN FILED Noms. 1905.

3 SHEETS-SHEET 3.

WITNESS wan/ww INVENTOR UNITED` STATES PATENT OFFICE. oLIvER M. MoWAT, orl MdKEEsPoRT, PENNSYLVANIA, AssiGNoR To NA- TIoNAL TUBE COMPANY,- oF P1TTsBURG, PENNsYLvANiA, A CORPORA- TION OF NEW JERSEY.

TAF-eralNouan;I MACHINE.

T Specification of Letters Patent.

Appunti@ filed November s,19o5. sans No. 285,679.

Patented June 11, 1907.

tion of the same; Fi 3 is a front elevation partl in section; an Fig. 4 is a face view of the c uck Withthe tap in position therein.

The invention is designed' vto provide a simple machine, by means of which the point A ends of tap's for pipe couplin s and the like centric to the cutting may be rapidly and accurate y round conpomts of t e taps and ground with the desired taper and the proper mounted to revolve on a fixe clearance, and the invention consists in the combination with a suitable, inding wheel n? axis, of a tap holding and turning chuck havin novel means for holding the tap in the chuc and proper relation to said wheel, together with an eccentricguide member, in-co-o erative relation with the chuck, to actuate t e latter ina marmer to provide for the backing 0H, or

clearance, ofthe ta points.

The lnvention a so consists inthe novel construction, arrangementand combination 'of the parts, all substantially as hereinafter described and claims.

,In the accompanying drawings, 2 'designates a suitable frame upon .which is journaled a horizontal shaftB carrying the grindpointed/out in the appended f ing wheel 4 and driven by the pulleys 5. 6 is the tap-holding chuck having the. adjustable center 7 for the end ofthe tap 6 and the jaws 7 for clamping the cutting portion thereof.

Frequently intempering the taps become slil htly Warped. l-

' order to insure the taper point of the tap being ground concentric with its center the ta ffis gras ed with its point rejecting only t e require amount beyond t e face of. the chuck to enable the desired length of taper to be ground by the grinding wheel without bringin the face of the chuck into The adjustable center 7 is shifted-in the chuck so as to center l and support the inner end of thetap while it islbeing ground.

, The grasping jaws of the chuck are s ecially formed'to grasp and hold the hig y tempered points of the tap-bits, being rovided with recesses `7a in their clam in aces, as shownin Fig, 4, into which t e enter and 'aref revented from injury by contact with suc faces. The saidv chuck is mounted upon a base portion 8 which is arit points,

ranged to slide transversely of the machine l' upon the guides 8". The base 8 is ieldingly connected by means of the rod 19y with the auxiliary slide 8, and the base 8 and slide 8?- are actuated transversely to the face of the chuck by means of the hand wheel and screw 19. The base 8 is also adapted to be` moved toward and from' the slide 8a by means ofthe eccentric guide to be presently described. The base portion 8 and slide 8a are in turn mounted u on sub-base 10 for movement longitudina ly toward and away from the face of the grinding wheel 4, and for this urpose the actuating screw and hand whee 11 a 1 e rovided. The sub-base 10 is pivotedlto t e horizontal lane, and its swingin movement is limited y a depending stu 13, which passes through a slot 14 (shown by dotted ame of the machine at 12 to swing in a nes in Fig. 2), its adjustment being secured by nut 1,5 on the lower threaded end of the stud. This swinging movement ofthe chuck as a whole, about the center 12, enables the end of the tap to be brought into any desired angular relation to the face ofthe grinding wheel, whereby the desired taper may `be obtained.

16 is the eccentric guide which is fixed to the arm2a of the frame 8a. This guide has a `curved `face 16l1 which is eccentric with respect to the centerof the chuck, the amount of its eccentricity being equal to the amount of bac-king .ofi or clearance to be given the ends of the tap bits. Secured to the taprotating hand wheel 17 of the chuck 6, and equally spaced thereon; are as many lugs or projections 18 as there are cutting edges on the tap to be ground. These lugs or pro'ections are peripherally located so that W en the Wheel 17 is turned in the direction of the IOS 8 in a direction transverse to its longitu- Y dinal axis, so that when the tap is turned in` the chuck upon the center 7 by means of the said hand Wheel, the bits, instead of being ground to a true circle, are ground with an eccentricity, or clearance, equal to that of the guide-face 16a. The movement of the chuck im arted thereto by the said guideface is resisted by a spring 19, seated upon a rod 19 connected to the chuck base at 20, the spring being coniined between the rodbearing 21 and the nut 22 at the free end of said rod. The purpose of this spring is to effect the return movement ofthe chuck and its support when moved by the eccentric in the manner described, and to insure an exact movement thereof.

.The guide 16' is made removable, so that if desired diflerentguides may be used'interchangeably. upon the machine in order to `give any desired clearance grind.

23 is the water-supply pipe for the grinding Wheel, fed by a suitable pump 24, drawing its supply from the tank 25, and 26 is a guard i for the grinding wheel.

By'means of the arrangement of the chuck above described, it will be readil seen thatiy operated to bring tbetap 'points into correct relation.

it can be quickly and convenient tothe grinding Wheel and that the grinding i v may be conveniently and rapidly perfected.

It will be obvious that various changes may be made in the details of construction .and arrangement which I have herein shown and described, Without departing from the spirit and scope of my invention as defined in and .by the appended claims 1. In a tap-grinding machine, the combination with a grinding Wheel rotating upon a' ixed axis, of a tap holding chuck having a longitudinal and an angular adjustment, and means whereby as thetap is rotated in the chuck, the latter is moved With respect to the .wheel substantially as described.`

2: In a tap-grinding machine, the combination vt/ ith a grinding Wheel, of a movable tapeholding chuck, having a. ta -rotating member, a ixed eccentric guide adjacent to v lthe said member, and means on .said member turned; substantially as described.

'a longitudinally. and -a my hand.

With the said guide vvhen the contactin g substantially as demember is rotated; scribed.

3. In a tap-grinding wheel arranged to rotate about v'a ixed axis, a tap-holding 4chuck having' a tap-turning member, a support for t e chuck having means `for permitting the chuck to be move longitudinally,' `transversely and angularly with respect to the Wheel, and eccentricv means for moving the chuck transversely to its `longitudinal axis when said member is machine, a grindingl 4. In a tap-grinding machine, the combination with a tap-holding chuck movable transversely with respect to` its longitudinal axis, and having` a tap-turning memberA rovide'd with spaced lugs or projections, a ed guide member having aneccentric face arran ed vto be engagedby 'ec ons, and a spring acting u on the chuck in the opposite direction; su stantially as describe( 1 `5. 'Ina tap-grinding( machine, a tap-holdin and rotating chuc aftransverselyvmovab e base upon which vthe chuck is mounted, sub-base'upon which the rst nainedbase is mounted', and eccentric means automatically coperating With the-chuck to forma clearance 'grind as the tap is rotated in the chuck; substantially as described.

' 6. In a tap-grinding machine, the combi-g nation of a Agrinding Wheel, a tap-holdin and rotating cbhuck mounted forlongitudina lateral vand angular movement, and means s aid lugs or prolarly adjustable for effecting la lateral movement of said chuck when the tap is rotated;.substantially as described. v

In testimony W -7 x OLIVER 5M. MoWA'r. l

Witnesses: f

- GEO. B. BLEMING,

RICHARD DrLrr'rLE. v

, 85 erreof, I have hereunto'set 

